improve tests

spec/CloudCode.spec.js

@@ -225,7 +225,7 @@ describe('Cloud Code', () => {
     obj.set('foo', 'bar');
     try {
       await obj.save();
-      expect(false).toBe(true);
+      fail('should not succeed');
     } catch (e) {
       expect(e.message).toBe('Invalid field name: length.');
     }

spec/ParseObject.spec.js

@@ -728,15 +728,19 @@ describe('Parse.Object testing', () => {
     });
   });
 
-  it('cannot save object with className field', async () => {
-    const obj = new TestObject();
-    obj.set('className', 'bar');
-    try {
-      await obj.save();
-      expect(true).toBe(false);
-    } catch (e) {
-      expect(e.message).toBe('Invalid field name: className.');
-    }
+  it('cannot save object with invalid field', async () => {
+    const invalidFields = ['className', 'length'];
+    const promises = invalidFields.map(async field => {
+      const obj = new TestObject();
+      obj.set(field, 'bar');
+      try {
+        await obj.save();
+        fail('should not succeed');
+      } catch (e) {
+        expect(e.message).toBe(`Invalid field name: ${field}.`);
+      }
+    });
+    await Promise.all(promises);
   });
 
   it('old attribute unset then unset', function (done) {

spec/ParseQuery.spec.js

@@ -2860,19 +2860,6 @@ describe('Parse.Query testing', () => {
     });
   });
 
-  it('object with length', async () => {
-    const TestObject = Parse.Object.extend('TestObject');
-    const obj = new TestObject();
-    obj.set('length', 5);
-    equal(obj.get('length'), 5);
-    try {
-      await obj.save();
-      expect(false).toBe(true);
-    } catch (e) {
-      expect(e.message).toBe('Invalid field name: length.');
-    }
-  });
-
   it('include user', function (done) {
     Parse.User.signUp('bob', 'password', { age: 21 }).then(function (user) {
       const TestObject = Parse.Object.extend('TestObject');